Cooling apparatus for heat-treated work using air jets



.Pune l0, 1947. w. LEHRER 2,422,105

COOLING APPAATUS FOR HEAT TREATED WORK USING AIR JETS Original FiledJune 3, 1943 2 Sheets-Sheet 1 (worneg vw. LEHRER June 10, 1947.

COOLING APPARATUS FOR HEAT TREATED WORK USING AIR JETS 2Sheets-Sheet 2Original Filed June 3, 1943 I l /l l l l l 1%/ ///l Smaentor A MLK/MH?(ltforneg Patented June 10, 1947 COOLING APPARATUS FOR HEAT-TREATED.WORK USING AIR JETS William Lehrer, Toledo, Ohio, assignor to SurfacelCombustion Corporation, Toledo, Ohio, a

corporation of Ohio 'continuation of application serial No. 489,567,June 3, 1943. This application October 19, 1945,

Serial No. 623,242

.6 Claims. 1

This` application is a continuation of my application lSerial No.489,567 led June 3, 1943.

The invention relates to heat treating furnaces of the type embodying anelongated cooling chamber for the controlled cooling of work afterheating. Certain steels are advantageously Iquickly cooled from above tobelow the critical temperature; and it is the object of the invention toprovide an improved cooling unit for thus initially quickly cooling theheated steel with a rapidly circulating gaseous cooling medium.

For a consideration of what I believe to be novel and my invention,attention is directed to the following specication and the claimsappended thereto.

In the accompanying drawings,

Fig. 1 is a diagrammatic side elevation of a heat treating furnaceembodying the present invention.

Fig. 2 is an enlarged vertical transverse section on line 2 2 of Fig. 1with some parts more or less diagrammatically shown.

Fig. 3 is an enlarged vertical longitudinal section on line 3--3 of Fig.1 with some parts more or less diagrammatically shown.

Fig. 4 is a fragmentary detail view on line -d of Fig. 2.

Referring to Fig. 1, the heat treating furnace comprises a heating zoneA, a quick cooling zone B, and a slow cooling zone C, in the ordernamed. The gaseous cooling medium is of such composition as toconstitute a protective atmosphere for the heated steel and thisatmosphere will prevail throughout the length of the furnace.

In the case of elongated work such as tubes or sheets (diagrammaticallyindicated at W in Figs. 2 and 3), a roller hearth conveyor 5 willordinarily be employed for supporting the work during its progressthrough the furnace. In the heating zone or chamber A, the heating meansmay comprise upper and lower rows of radiant tubes I0. To reduce heattransfer between the heating and quick cooling zones to a minimum, theconnecting passage therebetween is made as restricted as possibleconsonant with passage of the work therethrough. A vertically adjustabledoor 8 permits the effective height of the passageway to be adjusted asconditions may require. Water cooled wall sections 6 and i are desirablyprovided between said zones.

The quick cooling zone or chamber B comprises a horizontally disposedupper wall l5, a, horizontally disposed lower wall i6, and side walls iltherebetween. The aim of the present invention is to provideimprovements in means for forcibly circulating relatively great volumesof gaseous cooling medium into and out of contact with the heated steelpassing through the cooling chamber and withal to construct certainparts of the apparatus in such a way as to permit ready assembly of' thevarious separate parts in the field with minimum trouble and expense.

In the present invention there is provided above the cooling chamber B aplenum chamber i8 comprised of the horizontal wall i5, side walls 35 anda top wall E9. There is also provided below the cooling chamber a.plenum chamber i9 comprised of the horizontal wall i6, side walls 38 anda bottom wall iii. An upper blower 25 delivers gaseous cooling medium tothe upper plenum chamber i8 .and a blower 26 delivers the same kind ofcooling medium to the lower plenum chamber i9.

Gaseous cooling medium from the upper plenum chamber i8 is blastedagainst the upper side of the work by a plurality of nozzles 20 whichextend downwardly from the bottom of the plenum chamber and which extendcrosswise of the cooling chamber whereby the gas jet from each nozzle isin the form or a continuous sheet crosswise of the cooling chamber. Adamper 22 above each nozzle 20 permits adjustment of blasting effectlengthwlseof the cooling chamber.

Gaseous cooling medium from the lower plenum chamber i9 is blastedagainst the underside of the work by a plurality of nozzles 2i whichextend upwardly from the top of the plenum chamber and which extendcrosswise of the cooling chamber whereby the gas jet from each nozzle isin the form of a continuous sheet crosswise o the cooling chamber. Adamper 23 below each nozzle 2i permits adjustment of the blasting effectlengthwise of' the cooling chamber.

Ilihe upper blower 25 and the upper plenum chamber i8 are interconnectedby a conventional bolted flange connection 29; and the lower blower 26and the lower plenum chamber I9 are likewise interconnected by aconventional bolted flange connection 3l.

The joint between the top wall 28 of the upper plenum chamber and theside walls 35 is made gas-tight by a liquid seal comprising a liquidholding trough 3d which encircles the upper portion of the plenumchamber, thus permitting the top wall to be readily installed gas-tightin the eld. Thejoint between the bottom wall 30 of the lower plenumchamber and the side walls 38 is made gas-tight by a liquid seal'comprising a peripheral liquid holding trough 31 carried by the bottomwall 30, thus permitting the latter to be readily installed gas-tight inthe ileld.

The suction or intake side of the upper blower is connected by a pair ofreturn ducts 42 and 43 with the opposite sides of the upper portion ofcooling chamber B; and the suction or intake side of the lower blower 26ls connected by apair of return ducts 44 and 45 with the opposite sidesof the lower portion of the said cooling chamber. This system of returnducts from the opposite sides or `ooth the upper and lower portions ofthe cooling chamber is an important feature of the invention because theupper and lower portions of the cooling chamber are thereby madesubstantially independent of each other as regards circulation of thegaseous cooling medium.

At their intake ends, each of the return ducts is comprised of ahorizontally extending row of exhaust p'orts each provided with a damperto control its effective inlet. thereby permitting the exhaust effect tobe controlled lengthwise of the cooling chamber B. The exhaust ports forthe upper half of the cooling chamber are indicated at 4E and those ofthe lower half at di. The damper for the individual exhaust portscomprises an upright plate 52 xedly secured to an upright turnable shaft53 adapted to held in adjusted position by a clamping nut on the shalt.In Fig. 4, the shaft projects through the lower adjacent wall 55 of theduct 42. For the lower dampers the shaft will project th'rough the upperadjacent wall of the lower ducts 46 and A5.

Each of the upper return ducts i2 and 43 is made in upper and lowersections, and the joint therebetween is made gas-tight by a liquid sealcomprising a, liquid holding trough E@ which surrounds the lowersection, thus permitting the sections to be readily connected gas-tightin the held; and each of the lower return ducts 4d and i5 is also madein upper and lower sections and the joint therebetween is likewise madegas-tight by a liquid seal comprising a liquid holding trough 6i whichsurrounds the lower section, thus permitting the sections to be readilyconnected gastight in the field.

In each of thefour return ducts i12-d5 there is provided a heatexchanger means for cooling the spent cooling medium, the means for .theupper ducts being diagrammatically indicated at d8 and thosef or thelower ducts at as. Water pipes leadlng to and from the individual heatexchangers are indicated at 50.

The recirculating rate of the upper blower 25 may be controlled by amaster damper 58 and that of the lower blower 26 by a master damper 59.Make-up gas will ordinarily be supplied to the system at th'e intakeside of the respective blowers.

What I claim as new and desire to secure by Letters Patent is:

1. In apparatus of the class described, the combination of wall meansincluding top and bottom walls and right and left hand side wallsforming a treating chamber wherein material on passing therethrough maybe treated with gaseous treating medium, wall means including said topwall forming a first plenum chamber outside of said treating chamber forreceiving a supply of said treating medium from means including ablower, a first set of right and left hand suction conduits leading fromthe suction side of said blower and y communicating with' the upperportion of said treating chamber through the rightvand left hand sidewalls thereof for withdrawing spent treating medium therefrom, wallmeans including said therefrom. and nozzles extending' into saidtreating-'chamber `from the upper and lower plenum chambers fordirecting gaseous treating medium from the plenum chambers against theupper and lower sides, respectively, oi the said material moving throughthe treating chamber.

2. In the combination as set forth in claim l, each of said suctionconduits having a, joint between its ends and means comprising a liquidholding trough around each joint to make it gastight.

3. In apparatus of the class described, the combination of wall meansincluding upper and lower walls and right and left hand side Wallsforming a, treating chamber for material passing therethrough, wallmeans including a top wall and side walls above the said upper wallforming a plenum chamber for gaseous treating medium, a blower fordelivering said treating medium to said plenum chamber, nozzle means forblasting the top side of said material with' gaseous treating mediumfrom said plenum chamber, duct means leading from the treating chamberto the intake side of the blower for returning spent treating medium tothe circuit, and means comprising a, liquid holding trough encirclingthe upper portion of the plenum chamber to provide a gas-tight llointbetween the said top wall of the plenum chamber and the side wallsth'ereof.

4. In apparatus of the class described, the combination of wall meansincluding upper and lower walls and right and left hand side wallsforming a treating chamber for material passing therethrough, wall meansincluding a bottom wall and side walls below said lower wall forming aplenum chamber for gaseous treating medium, a blower for delivering saidtreating medium to said plenum chamber, nozzle means for blasting theunderside of said material with gaseous treating medium from said plenumchamber, duct means leading from the treating chamber to the intake sideof the blower for returning spent treating medium to the circuit, andmeanscomprising a liquid holding trough encircling the lower portion oithe plenum chamber to provide a gas-tight joint between the said bottomwall of the plenum chamber and the side walls thereof.

5. lIn apparatus of the class described, the combination of wall meansincluding upper and lower walls and right and left hand side wallsforming a treating chamber for material passing therethrough, meansincluding a top wall and side walls above the said upper wall forming aplenum chamber for gaseous treating medium, a blower for delivering saidtreating medium to said plenum chamber, nozzle means for blasting thetop side of said material with gaseous treating medium from said plenumchamber, means comprising a liquid holding trough encircling the upperportion of the plenum chamber to provide a gas-tight joint between thesaid top wall of the plenum chamber and the side walls thereof, ductsleading upwardly from the opposite sides of the upper portion of thetreating chamber to the intake side of said blower for returning spenttreating medium to the circuit, each of saidducts comprising upper andlower sections, and means comprising a liquid holding trough surroundingeach' the sections.

of said ducts at the joint between thereof to make said joint gas-tight.y

6. In apparatus of the class described, the combination of wall meansincluding upper and lower walls and right and left hand side wallsforming a treating chamber for material passing therethrough, wall meansincluding a bottom wall and side walls below said lower wall formingaplenum chamber for gaseous treating medium, a blower for delivering saidtreating medium to said plenum chamber, nozzle means for blasting theunderside of said material with gaseous treating medium from said plenumchamber, means comprising a liquid holding trough encircling the lowerportion of the plenum chamber to provide a. gas-tight joint between thesaid bottom wall of the plenum chamber and the side walls thereof, ductsleading downwardly from the opposite sides of the lower portion of thetreating chamber to the intake side of said blower for returning spent*treating medium to the circuit, each of said ducts comprising upper andlower sections, and means comprising a liquid holding trough surroundingeach of said ducts at the joint'between the sections thereof to makesaid joint gas-tight.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PA'I'ENTS Slenfeld Aug. 25, 1942

